In this article we will discuss about:- 1. Introduction to Packaging 2. Concept of Packaging 3. Factors Affecting Packaging 4. Metal Containers 5. Elements 6. Packaging Machinery.
Introduction to Packaging of Products:
In the modern world, most of the goods are available in packages. The packaging protects and preserves the goods and offers convenience in transport, handling and sale also. The goods in packaging should retain their original form, shape and properties. The packages should be convenient and attractive.
A primary package is the one which comes in contact with the product. Therefore, the selection of material plays a vital role and it should be compatible with the product to be packed. The main function of a transport package is to give the require protection to the packaged commodity against incidental hazards during transportation, handling and storage.
New Concepts in Packaging:
Plastics are penetrating and invading in all directions, be it automobiles, agriculture, pharmaceuticals, fertilisers and processed foods. These have emerged as a means of substitution and complementation particularly in packaging.
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Plastics as a means of packaging are replacing all conventional materials. During the last decade newer concepts based on plastics packaging have appeared in the developed countries. A number of these have already entered the Indian market in certain applications. However, an array of these concepts has yet to come. It will be worthwhile to evaluate as to what extent these concepts would have, relevance in India in promoting domestic and export packaging.
Before we list and evaluate all those concepts which have immediate relevance in product packaging applications in India, it will be useful to review the current developments. Plastics industry emerged in India with the development of petrochemical industry in the mid-sixties. In 1959, the production of low density polyethylene was started.
The introduction of high density polyethylene as a means of packaging, especially for the packaging of chemicals etc. in carboys and jerry cans was done by the Polyolfins India Ltd. HDPE containers for the packaging of edible oils were also introduced.
Currently, India produces a number of plastics materials. Of these, linear low density polyethylene, high density polyethylene, polypropylene, nylon-6, polyester, polyvinyl chloride, polystyrene and PET are widely used for making containers, bottles, crates, caps, closures, tubes, sacks, bulk containers, ropes, nettings, cups, trays, pouches, films, laminates etc.
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Plastics have become a dominating and dynamic means of packaging for the strengths they possess. And hitherto their disadvantages, if any, are largely being controlled and diluted by the development of basic polymers or the blending of other materials.
The research and development work of this type have made plastics as the most economical and prospective contender as the packaging means of tomorrow. These are the versatile properties of plastics which have made them a universal means of packaging.
Consumers have liked them; producers and packers have opted for them since these are economical, lighter, formable, stackable, recyclable, mouldable, easily acceptable on the filling, production and distribution lines, possessing convenience in terms of opening, closing and disposal, easily and excellently printable, efficiently sealable and storable.
Further, the relative consumption of energy in case of plastics is far less than glass, metal and other containers. It has been found that the relative cost differentials in case of plastics packaging are much lower when compared with corrugated boxes, tinplate containers, glass bottles etc.
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Viewing from other perspectives the developments in plastics packaging have also taken place from the view-point of its structure and flexibility. Initially, the containers were rigid. Currently, the developments are towards more lighter, transparent, see-through and multilayer, with an emphasis on reduced use of material with increased strength and improved packaging functions.
The development of performance plastics, copolymer of propylene, orientation of polyvinyl chloride, polyester, polypropylene; or very low density polyethylene, medium density polyethylene, nitrile resins, BAREX, etc. have made the plastics the most sought materials for packaging applications.
It will not be an exaggeration to say that the developments in plastics packaging have gone to multidimensional heights in terms of shapes of containers and closures; functions; printing facility; re-usability etc.
Plastics have accepted the challenges faced by the production engineers, marketing professionals and environmentalists. Only recently, in countries like Sweden and West Germany, there are certain controlled checks on the growth of plastics since these have reached the points of social and environmental threats. However, it must be conceded that the faults lie not with the plastics but to the level and rate of plastics consumption in packaging.
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Horizontal developments in plastics could be summarised as follows:
1. LDPE is used for the packaging of milk, soaps, detergents, sealants and wrapping materials. It is also used for the packaging of textiles, meats, frozen foods and horticulture products.
2. High density polyethylene finds applications made with the help of injection moulding, pallets, transport containers, bottle crates, other crates, flexible bulk containers, drums, blow moulded containers, films, sheets etc. Almost any product could be packed in the packages made of high density polyethylene.
3. Linear low density polyethylene, which possesses improved packaging properties, finds applications almost in those lines where LDPE has been applied.
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4. High molecular high density polyethylene is used for the packaging of flowers, foodstuffs, metal, fish, dairy products, clothes, books etc.
5. Polypropylene, which possesses more or less the same packaging properties in relation to HDPE, is used for the making of corrugated boxes, sacks, containers, films, laminates etc. for the packaging of chemicals, foods, fruits and vegetables etc.
6. Plastics, especially polystyrene and ethylene in expanded forms like cups, moulded structures etc., are used for the packaging of ice-creams, processed foods, electronics etc.
Noticeable vertical developments in plastics packaging could also be summarised as follows:
1. PVC during the initial period was applied for the packaging of non-food products, basically for the reason it contained vinyl chloride monomer—a suspected cause for the cancer. Because of intensive research and development work, food grade PVC has now been developed and these are now being used for the packaging of foods within acceptable rules. Further, orientation of poly vinyl chloride also enabled PVC to be used for the packaging of liquid foods.
2. Newer plastics like Alathon have been developed. It is basically a high density polyethylene polymer, is an improved version which offers higher polymer properties, and at the same time reduced consumption of materials.
3. Barrier materials like ethyl vinyl alcohol, nylon modified, ethylene vinyl acetate etc., in the presence and in some cases without the presence of tie layers, are being used to make multilayer films, laminates and bottles to improve their barrier properties as compared to that of glass.
Factors Affecting Packaging:
The fundamental factors affecting the design of a package are:
a. Product characteristics;
b. Modes of distribution; and
c. Marketing considerations.
The technical considerations which influence the package design are:
i. Hazards during transportation, such as shocks and vibrations transmitted to the product during transportation by rail, road, sea and air.
ii. Hazards during handling, such as impact due to drop, compression and puncture
iii. Hazards during storage (for example, the greater the stacking height in a warehouse, the more the need for a strong and rigid package to withstand compression) and
iv. Hazards due to climatic changes.
The packaging should be of best quality and be produced at competitive costs.
Various materials used for packaging are plastics, metals, glass wood and paper (including corrugated packaging).
New mechanical packaging lines are employed and fully automated high-speed production systems are being introduced. Traditional packaging materials like tin and glass are being forced to give way to plastics and paper. The whole concept is to give the consumer the most economical packing material.
Traditional packing materials like paper, wood and tin are increasingly becoming scarce and attempts are being made to substitute them by others. Plastics are now being used on a large scale for packaging due to their inherent advantages, such as light weight, strength, chemical resistance, flexibility, excellent barrier properties and aesthetic appeal.
The use of plastics for packaging is increasing both in quantum and variety. A number of plastic raw materials are consequently available in various forms, such as films, sheets, pouches, bottles, jars, jerry cans, sachets and containers (rigid and flexible) of all shapes and sizes. These products are normally based on a single plastic material.
For special applications more than one plastic raw material may be used. Co-extruded or laminated films, sheets and bottles based on two or more plastic raw materials extruded together are examples of such types.
The major drawback with plastics is migration of chemical constituents in the packaging material to the packed material due to intimate contact. Since there is always a possibility of transfer of a part of the plastic package to the contents, care should be taken to select so as to ensure that such transfer is at a minimum and the substances which do migrate from the package to the packed material are within limits and cause no toxic hazards, when consumed.
The ministry of health and family welfare has adopted under the Prevention of Adultration Act (PAA) the standards on polyethylene, styrene polymers, polyvinyl chloride, polypropylene and ionomers and has stipulated that plastic packaging for foodstuff should conform to these specifications.
Similarly standards have been formulated for finished containers namely blow-moulded HDPE containers, flexible packs for packing vanaspati polyethylene pouches for liquid milk, flexible packaging material for packaging for refined edible oils.
Other I.S. Specifications:
Plastic containers for reserve fuel, polyethylene containers for transport of materials, blow-molded polyolefin containers upto 30 litres, plastic containers for pharmaceuticals, HDPE containers for liquid pesticides, HDPE woven fabric for packing of textiles, HDPE woven sacks for packing pesticides, high density polyethylene (HDPE) woven sacks for packing fertilisers, polypropylene (PP) woven sacks for packing fertilisers, HDPE woven sacks for packing cement, and polypropylene (PP) woven sacks for packing cement.
Plastic Fabric Packs:
Fabric made from weaving of monoaxially oriented tapes of HDPE or PP is finding increased use vis-a-vis jute in a number of industries. This is primarily because of the superior chemical resistance and good strength of such fabrics.
While fabric made from PP is commonly used the world over, in India HDPE fabric is more popular. HDPE woven sacks are finding use in the packing of a variety of products, such as fertilisers, foodgrains, pesticides, cement, wheat, flour milk powder and sugar.
Metal Containers for Packaging:
The main metals used in packaging are mild steel sheet, tinplate terne plate (a mild steel coated with a tin or lead alloy), galvanised mild steel sheet, stainless steel, aluminium alloys and aluminium. Tinplate is the principal material for metal boxes and cans. Aluminium and its alloys have long been used for the manufacture of rigid containers, although not to the same extent as tinplate.
Aluminium is also used in the form of foil (both alone and laminated to other materials) and for collapsible tubes. Metal containers, specially tinplate and aluminium are non-toxic and possess excellent barrier properties and due to their basic strength they afford good protection to the contents.
Round open-top sanitary can (OTS) is a rigid metal container which can be hermetically sealed for packaging of thermally and non-thermally processed foods and drinks like fruit and vegetable products, synthetic beverages, meat and fish products, dairy products, instant coffee and instant tea. The container withstands the temperature, pressure, vaccum, during processing and prevents entry of micro-organisms.
Glass Containers:
Glass, in spite of its fragility, still holds its place as a choice material for packaging a variety of products. Glass is inert and does not react with most products. It is economical and can be readily formed into desired sizes and it is excellent for merchandising and display purposes.
The biggest users of glass containers are the manufacturers and processors of food, beverages, drugs, cosmetics, household products and industrial chemicals. The major drawback with glass containers is that they are not shock resistant.
Others:
Jute and wood are the earliest packaging materials and are being used extensively in many applications. Wood containers are mainly used as transport containers, particularly for heavy machinery and engineering goods. Public awareness regarding conservation of forests is making consumer industry to go for alternate materials like, corrugated packaging, fibre board containers made from agricultural residues.
Jute is mainly used for packaging grains, fertilisers and cement. Jute has been facing serious competition from plastics and multi-wall paper sacks. Now improved jute bags with paper or plastic lamination are being increasingly used for packaging of milk powder and fertilisers.
“A package should save more than it costs”, is a simple but profound philosophy. Aseptic packaging is rapidly generating fundamental changes in the handling of many perishable foods like milk, juice and other products.
Aseptic packaging works on three fundamental principles:
i. Sterilisation of packaging material,
ii. Creation of a sterile environment while filling the product, and
iii. Production of packaging material which is hermetically sealed to prevent reinfection.
With aseptic packaging, distribution and storage are possible without refrigeration and the packs have a shelf-life of several weeks, during which vitamins and other nutrient values are maintained.
The long storage period at room temperature is made possible through Ultra High Temperature (UHT) treatment. In the case of milk, for instance, UHT imparts a brief heat shock-about 140 degree Celsius-for-two to four seconds, killing bacteria and thereby maintaining sterility.
Pasteurised milk needs to be refrigerated continuously, at not more than 8 degree Celsius. This way it remains fresh for a few days. With UHT treatment and aseptic packaging, milk can be stored for several weeks at room temperature with flavour and quality maintained.
Elements of Packaging:
There are three major element in any packaging operation:
1. The Package:
It should protect the product from environmental, transportation and handling hazards. It should also preserve the product without deterioration during the expected shelf life. And most important, it should convey necessary information such as quality, quantity, price, date of packing and brand name to take full advantage of “brand loyalty”.
2. The Packaging Machinery:
These machines should pack the product in required dosages without extensive variations, give the required output and be flexible enough to accommodate different pack sizes without major modifications.
3. The Operating and Maintenance Personnel:
People making the packaging machines, should have sufficient skills to operate and maintain the machinery at rated outputs, within normal allowable spoilage.
There are problems of compatibility of the above three components especially in the case of mass-produced items requiring high speed operations. It becomes difficult to pinpoint responsibility in the case of a malfunction in the packaging line on either the packaging material or the machine or the personnel.
System packaging overcomes this problem because of a single supplier of packaging material and packaging machinery, with training being provided to the operators and maintenance personnel. The system supplier ensures compatibility of the above three elements by extensive trials at his end as well as that of the manufacturer-cum-packer.
Cekatainer Lined Carton System:
The lined carton- Cekatainer— consists of a duplex board carton printed with the required design and an inner heat-sealable liner glued to the carton. The carton provides mechanical strength and makes the pack easy to handle and distribute.
It also provides excellent scope for decoration and multicolour printing. The heat-sealable liner provides physical, chemical and biological protection i.e. it protects the contents from losing or absorbing moisture, from loss of aroma or odour pick-up, from oxidation and from the effect of light. Cekatainers are characterised by flexibility and economy. They are also hygienic and pilfer proof.
There is flexibility in varying the carton and liner material independently of each other. There is flexibility of format i.e. the carton’s length, width and height can be varied within wide limits. There is also flexibility in carton construction.
Vacuum Packaging:
A vacuum package offers a very special kind of protection to the product. This protection is due to the fact that the product is hermetically sealed in a vacuum in a film pouch. The decisive factor here is that there is no more oxygen inside the package. For foodstuffs this means that the growth of microorganisms is greatly inhibited, and this in return increases a product’s shelf life considerably.
Vacuum packaged products are safely protected from spoilage, dehydration, changes in flavour, contact and loss in weight. They are presented hygienically and attractively in self-serve packages. Pure vacuum pack are pressed together by the outside air pressure.
Paper Conversion:
Paper conversion is the process of converting paper into useful products which have various end uses especially packaging. Packaging is a multidimensional, multi-disciplinary, dynamic art, science and technology, to protect, preserve and present the product. Paper conversion machinery is suitable to produce paper cones, paper tubes, paper cores, composite containers etc.
Paper cone is a vital packaging material in the textile industry and is used in winding of yarns. Paper tubes and cores have various end uses such as filament yarn winding, BOPP film winding, paper reel winding etc., composite containers are used for the packaging of innumerable products like spices, pharmaceuticals, food products, motor oils etc.
Uncasers and Case Packers:
Fully automatic uncasers and casepackers can handle speeds of up to 480 bottles per minute, with half depth cases. Uncasers can handle case patterns up to 4 wide in 4 x 3, 4x 4, and 4×6 configuration. They operate on the principle of continuous moving V-belts, which are guided to firmly hold the bottle and lift them from the case, before delivering them on a moving conveyor, to the bottle washer. The entire lifting mechanism is mounted on two supporting structures.
The new range of uncasers has several advanced and innovative features over the uncasers available earlier in the market. The most remarkable development has been the quick belt change. In the older machines in the event of a belt snapping, the replacement took a quarter of a shift to change, this can now be done in minutes.
To accommodate the difference of height from one bottle to another in product change all that is required to be done is the loosening of 8 bolts and jacking, this is accomplished conveniently through a gear box in a few minutes.
Safety has been incorporated into the design. In the event of a down the line hold up, a micro switch activates a timer, that stops the machine after a fixed time interval, and a pneumatically operated roller prevents any more cases from entering.
In the event of a bottle being stuck in the case there are rollers that hold the case down, and further vertical hanging plates that remove the bottle out of the case. The infeed rubber conveyor runs on spring mounted rollers that prevent locking of the case.
Casepacker places the bottle back in the case, after filling and capping. They work with the same class and bottle configuration and perform exactly the opposite function of the uncaser, and operate between 18 and 21 cases a minute.
This machine consists of four main parts, the bottle infeed conveyor and shuffler, the bottle stopper and drop mechanism, these two being on the top. Below is the case infeed conveyor and stop mechanism, and finally the case elevating system.
This is a complex and highly sophisticated machine that is user-friendly, and easy to handle. The bottles arrive on four chains and are diverted with a S profile guide to prevent excessive bottle pressure buildup of the shuffler. Shuffling is done by an eccentric cam and a pneumatic system that arranges bottles in four rows.
Besides driving the monotony out of the job and employing several people, these machines require just the normal maintenance.
Packaging Machinery:
Packaging machinery can be broadly classified into five categories:
(a) Conversion machinery for production of packaging such as a tin can manufacturing line.
(b) Usage machinery for carrying out the operation of actually packing the product in the pack.
(c) Testing equipment for testing various properties of packaging raw materials as well as on-line quality control during packaging.
(d) Auxiliary equipment for packaging accessories such as labelling machines for glass bottles or gum tape dispenser for corrugated boxes, collators for unitising retail packs; and
(c) Package handling equipment such as conveyors and elevators.